In the past 40 years following the development of the plate tectonic paradigm, there has been a revolution in our understanding of the multiple and interacting cycles within and at the surface of the Earth.

This course focuses on:

• The nature of these cycles from those involving whole-mantle processes to the exchanges taking place between and within the lithosphere, hydrosphere, and atmosphere.
• Biological cycles of carbon, sulfur and iron are fundamental for the evolution of Earth's crust and mantle. 
• Major cycles include the downwelling (subduction) of lithospheric plates at subduction zones constituting the primary driver of plate tectonics. Some of the components of subducted lithosphere, including seawater, are transferred to the mantle at relatively shallow depths, and become involved in the melting cycles that lead to arc magmatism forming the primary building block of the continental crust, and re-emergence of recycled seawater. Subsequent mixing of other lithospheric components within the mantle and the partial melting of recycled mantle components occures at locations including mid-ocean ridges and hot-spots.
• In addition to the cycle of ocean crust creation at mid-ocean ridges, the thermal energy released at the ridges drives the cycling of the oceans through the rocks in the vicinity of the ridge crest, which result in important chemical exchange. 
• Rates of sea floor spreading and accompanying carbon dioxide emission are the fundamental controls on the global carbon cycle and long-term climate moderators.
• The spectacular biology and chemistry of the "hydrothermal" vents at the sites of hot fluid return to the oceans have only been recognised in the past 30 years. Similarly, pulses of intense igneous activity and degassing may be implicated in global extinction events. The interplay between these long term biogeochemical cycles and climate are most vividly illustrated  by the study of paleooceanography.  The collective improvement in our understanding of the paleo-climate records has been critical in allowing Earth scientists to put recent climate change forced by human interactions with the climate system into proper context. 

This course will detail the evolution the science that has lead to a more fundamental understanding of these ocean and climate interactions.

Note: Graduate students attend joint classes with undergraduates but will be assessed separately.

On satisfying the requirements of this course, students will have the knowledge and skills to:

1. Quantitatively analyse the Global energy Balance in the context of modern Global change.
2. Understand in detail the positive and negative feedbacks with the carbon cycle and the differing timescales that these changes take place.
3. Understand the radiogenic isotope tracers that allow the analysis of geochemical cycling in the mantle.
4. Understand how stable isotopes and other geochemical tracers have allowed the development of paleocean and paleoclimate research.

Assessment will be based on:

• In class exams and practicals 70%
• Class participation 10%
• Presentations 20%

35 hours Lectures, 30 hours Seminars

Bachelor degree; with first year Chemistry.

Chemistry to a first year level.